1. Technical Field
The present disclosure relates to surgical fastener applying apparatus and more particularly to surgical fastener apparatus that employs a fastener forming mechanism that includes a linkage system for sequentially applying a plurality of surgical fasteners to body tissue.
2. Background of the Related Art
Commercially available surgical fastener applying apparatuses wherein tissue is first grasped or clamped between opposing jaw structures and then joined by means of surgical fasteners are well known in the art. The fasteners are typically in the form of surgical staples however, other surgical fasteners may also be utilized, for example, clips or two part polymeric surgical fasteners.
To form the surgical fasteners, manufacturers typically employ an actuation mechanism that includes or is in operative communication with a wedge shaped sled that moves axially towards a distal end of a loading unit associated with the surgical fastener applying apparatus. The loading unit may be a disposable loading unit (DLU) or a single use loading unit (SULU). Additionally, the loading unit may be of the straight or curved type. Typically, the sled engages a corresponding pusher that moves orthogonally relative to an axis defined by the loading unit of. The pushers are configured to drive a corresponding staple through tissue and against a receiving pocket of an anvil associated with the surgical fastener applying apparatus to form the staple and close tissue. In this instance, the staples are fired sequentially, thus, minimizing the firing force and the size of a distal end of the surgical fastener applying apparatus. Accordingly, surgical fastener applying apparatuses of this type are well suited for use in laparoscopic procedures.
Costs associated with the manufacturing process of the above-referenced actuation mechanism and sleds associated therewith are relatively high due to design constraints associated with the sled and/or a driving mechanism employed to move the sled. Additionally, because the size of the loading unit is proportionate to the size of the sled and/or driving mechanism, the loading unit is typically larger than would be desired. Accordingly, it may prove useful to minimize the size of the loading unit while maximizing a mechanical advantage at the end of forming a staple.